Collapsed school in Mexico quake kills at least 25

The three-story school structure had pancaked into a pile of concrete slabs. The bodies of 21 children and four adults had been pulled out. But still sounds came from the collapsed structure early Wednesday - nobody knew if they were survivors pounding for help, or simply the noises of shifting rubble.

After a wing of the Enrique Rebsamen primary and secondary school collapsed in Tuesday's magnitude-7.1 earthquake, rescuers dug at the pile of rubble and soldiers wedged in wooden beams to try to prevent it from crumbling further.

"We managed to get into a collapsed classroom. We saw some chairs and wooden tables," Serrano said. "The next thing we saw was a leg, and then we started to move rubble and we found a girl and two adults - a woman and a man."

None of them was alive.

The rescuers left them there. There was no way to get them out.

Outside the school gates, rumors ran through the crowd of anxious parents that two families had received Whatsapp messages from girls trapped inside. Nobody could say for sure whether it was true.

People desperately trying to find their loved ones in Mexico City where a school collapsed. Children inside possibly stuck in the rubble. pic.twitter.com/6vBjI6g6bS